Thanks for the feeback. As I understand it, the NXT asset exchange was easier to use for three reasons:

1) Buying NXT could be done by sending BTC to an address.

2) There exists a website where you can easily see a list of existing assets.

3) The trades were completed quickly.

1) and 2) are not handled by the protocol, they are just external services that no one has yet set up for Counterparty. Moreover, I know that we have people that are currently working on them right now. With regard to 3), I can say that your trades with Counterparty would have been completed very quickly, too, if you used XCP, Counterparty's native currency, instead of BTC, to make your trades. Because of 1), Counterparty users are inclined to buy assets with BTC rather than XCP, which is much slower. Of course, NXT could never support trades with BTC.